Add a simple option parser.

The option parser takes argc, argv, an array of struct option
and a usage string.  Each of the struct option elements in the array
describes a valid option, its type and a pointer to the location where the
value is written.  The entry point is parse_options(), which scans through
the given argv, and matches each option there against the list of valid
options.  During the scan, argv is rewritten to only contain the
non-option command line arguments and the number of these is returned.

Aggregation of single switches is allowed:
  -rC0 is the same as -r -C 0 (supposing that -C wants an arg).

Every long option automatically support the option with the same name,
prefixed with 'no-' to unset the switch. It assumes that initial value for
strings are "NULL" and for integers is "0".

Long options are supported either with '=' or without:
  --some-option=foo is the same as --some-option foo

Acked-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Pierre Habouzit <madcoder@debian.org>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
This commit is contained in:
Pierre Habouzit 2007-10-15 01:35:37 +02:00 committed by Junio C Hamano
parent 09149c7809
commit 4a59fd1312
3 changed files with 204 additions and 2 deletions

View file

@ -290,7 +290,7 @@ LIB_H = \
run-command.h strbuf.h tag.h tree.h git-compat-util.h revision.h \
tree-walk.h log-tree.h dir.h path-list.h unpack-trees.h builtin.h \
utf8.h reflog-walk.h patch-ids.h attr.h decorate.h progress.h \
mailmap.h remote.h transport.h
mailmap.h remote.h parse-options.h transport.h
DIFF_OBJS = \
diff.o diff-lib.o diffcore-break.o diffcore-order.o \
@ -313,7 +313,7 @@ LIB_OBJS = \
alloc.o merge-file.o path-list.o help.o unpack-trees.o $(DIFF_OBJS) \
color.o wt-status.o archive-zip.o archive-tar.o shallow.o utf8.o \
convert.o attr.o decorate.o progress.o mailmap.o symlinks.o remote.o \
transport.o bundle.o walker.o
transport.o bundle.o walker.o parse-options.o
BUILTIN_OBJS = \
builtin-add.o \

167
parse-options.c Normal file
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@ -0,0 +1,167 @@
#include "git-compat-util.h"
#include "parse-options.h"
#include "strbuf.h"
#define OPT_SHORT 1
#define OPT_UNSET 2
struct optparse_t {
const char **argv;
int argc;
const char *opt;
};
static inline const char *get_arg(struct optparse_t *p)
{
if (p->opt) {
const char *res = p->opt;
p->opt = NULL;
return res;
}
p->argc--;
return *++p->argv;
}
static inline const char *skip_prefix(const char *str, const char *prefix)
{
size_t len = strlen(prefix);
return strncmp(str, prefix, len) ? NULL : str + len;
}
static int opterror(const struct option *opt, const char *reason, int flags)
{
if (flags & OPT_SHORT)
return error("switch `%c' %s", opt->short_name, reason);
if (flags & OPT_UNSET)
return error("option `no-%s' %s", opt->long_name, reason);
return error("option `%s' %s", opt->long_name, reason);
}
static int get_value(struct optparse_t *p,
const struct option *opt, int flags)
{
const char *s;
if (p->opt && (flags & OPT_UNSET))
return opterror(opt, "takes no value", flags);
switch (opt->type) {
case OPTION_BOOLEAN:
if (!(flags & OPT_SHORT) && p->opt)
return opterror(opt, "takes no value", flags);
if (flags & OPT_UNSET)
*(int *)opt->value = 0;
else
(*(int *)opt->value)++;
return 0;
case OPTION_STRING:
if (flags & OPT_UNSET) {
*(const char **)opt->value = (const char *)NULL;
return 0;
}
if (!p->opt && p->argc <= 1)
return opterror(opt, "requires a value", flags);
*(const char **)opt->value = get_arg(p);
return 0;
case OPTION_INTEGER:
if (flags & OPT_UNSET) {
*(int *)opt->value = 0;
return 0;
}
if (!p->opt && p->argc <= 1)
return opterror(opt, "requires a value", flags);
*(int *)opt->value = strtol(get_arg(p), (char **)&s, 10);
if (*s)
return opterror(opt, "expects a numerical value", flags);
return 0;
default:
die("should not happen, someone must be hit on the forehead");
}
}
static int parse_short_opt(struct optparse_t *p, const struct option *options)
{
for (; options->type != OPTION_END; options++) {
if (options->short_name == *p->opt) {
p->opt = p->opt[1] ? p->opt + 1 : NULL;
return get_value(p, options, OPT_SHORT);
}
}
return error("unknown switch `%c'", *p->opt);
}
static int parse_long_opt(struct optparse_t *p, const char *arg,
const struct option *options)
{
for (; options->type != OPTION_END; options++) {
const char *rest;
int flags = 0;
if (!options->long_name)
continue;
rest = skip_prefix(arg, options->long_name);
if (!rest) {
if (strncmp(arg, "no-", 3))
continue;
flags |= OPT_UNSET;
rest = skip_prefix(arg + 3, options->long_name);
if (!rest)
continue;
}
if (*rest) {
if (*rest != '=')
continue;
p->opt = rest + 1;
}
return get_value(p, options, flags);
}
return error("unknown option `%s'", arg);
}
int parse_options(int argc, const char **argv, const struct option *options,
const char *usagestr, int flags)
{
struct optparse_t args = { argv + 1, argc - 1, NULL };
int j = 0;
for (; args.argc; args.argc--, args.argv++) {
const char *arg = args.argv[0];
if (*arg != '-' || !arg[1]) {
argv[j++] = args.argv[0];
continue;
}
if (arg[1] != '-') {
args.opt = arg + 1;
do {
if (*args.opt == 'h')
usage(usagestr);
if (parse_short_opt(&args, options) < 0)
usage(usagestr);
} while (args.opt);
continue;
}
if (!arg[2]) { /* "--" */
if (!(flags & PARSE_OPT_KEEP_DASHDASH)) {
args.argc--;
args.argv++;
}
break;
}
if (!strcmp(arg + 2, "help"))
usage(usagestr);
if (parse_long_opt(&args, arg + 2, options))
usage(usagestr);
}
memmove(argv + j, args.argv, args.argc * sizeof(*argv));
argv[j + args.argc] = NULL;
return j + args.argc;
}

35
parse-options.h Normal file
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@ -0,0 +1,35 @@
#ifndef PARSE_OPTIONS_H
#define PARSE_OPTIONS_H
enum parse_opt_type {
OPTION_END,
OPTION_BOOLEAN,
OPTION_STRING,
OPTION_INTEGER,
};
enum parse_opt_flags {
PARSE_OPT_KEEP_DASHDASH = 1,
};
struct option {
enum parse_opt_type type;
int short_name;
const char *long_name;
void *value;
};
#define OPT_END() { OPTION_END }
#define OPT_BOOLEAN(s, l, v, h) { OPTION_BOOLEAN, (s), (l), (v) }
#define OPT_INTEGER(s, l, v, h) { OPTION_INTEGER, (s), (l), (v) }
#define OPT_STRING(s, l, v, a, h) { OPTION_STRING, (s), (l), (v) }
/* parse_options() will filter out the processed options and leave the
* non-option argments in argv[].
* Returns the number of arguments left in argv[].
*/
extern int parse_options(int argc, const char **argv,
const struct option *options,
const char *usagestr, int flags);
#endif